Composition for forming adhesive layer of dicing film, and dicing film

ABSTRACT

There are provided a composition for forming an adhesive layer of a dicing film, including: a polymer additive including at least one polymer selected from the group consisting of a polymer containing a (meth)acrylate-based functional group and a non-polar functional group, a (meth)acrylate-based polymer containing at least one fluorine, and a silicon-modified (meth)acrylate-based polymer containing a reactive functional group; an adhesive binder; and a photoinitiator, wherein a weight ratio of the polymer additive to the adhesive binder is 0.01% to 4.5%, a dicing film including an adhesive layer including the composition, a dicing die bonding film including the dicing film, and a method for dicing a semiconductor wafer using the dicing die bonding film.

FIELD OF THE INVENTION

The present invention relates to a composition for forming an adhesive layer of a dicing film, and a dicing film.

BACKGROUND OF THE INVENTION

In general, a process of manufacturing a semiconductor chip includes forming micropatterns on a wafer, and polishing the wafer so as to satisfy the standards of the final device and packaging.

The packaging process includes: a wafer inspection process for inspecting defects of semiconductor chips; a dicing process for cutting the wafer to separate into individual chips; a die bonding process for attaching the separated chips to the mounting plate of a lead frame or a circuit film; a wire bonding process for connecting a chip pad equipped on the semiconductor chip with the circuit pattern of a lead frame or a circuit film using an electrical connection means such as a wire; a molding process for covering the outside with an encapsulant so as to protect the internal circuit and other components of the semiconductor chip; a trim process for cutting a dambar connecting leads; a forming process for bending the lead to a desired shape; and a process of inspecting a finished product for inspecting defects of the finished package, and the like.

In the dicing process, a wafer is cut to a predetermined thickness using a diamond wheel and the like. Herein, to fix the wafer, a dicing film is laminated to the back side of the wafer under appropriate conditions, and then the process is progressed. To attach diced individual chips to a circuit board, a die bonding film is used.

Meanwhile, the dicing process includes the steps of cutting a semiconductor wafer with a dicing blade, irradiating UV to the base film of the semiconductor wafer, and picking up individual chips separated by the cutting of the semiconductor wafer, but there were problems in that fixation between films occurs during the pick-up process, and that due to excessive peel strength between films, a success rate of picking up chips is lowered or chip cracks are generated during pick-up.

DETAILED DESCRIPTION OF THE INVENTION Technical Objectives

It is an object of the invention to provide a composition for forming an adhesive layer of a dicing film for providing a dicing die bonding film that can prevent fixation between films in a dicing process to increase pick-up success rate, and exhibit relatively high die shear strength to prevent delamination due to degradation of adhesion strength.

It is another object of the invention to provide the dicing die bonding film.

It is still another object of the invention to provide a method for dicing a semiconductor wafer using the dicing die bonding film.

Technical Solutions

A composition for forming an adhesive layer of a dicing film is provided, including: a polymer additive including at least one polymer selected from the group consisting of a polymer containing a (meth)acrylate-based functional group and a non-polar functional group, a (meth)acrylate-based polymer containing at least one fluorine, and a silicon-modified (meth)acrylate-based polymer containing a reactive functional group; an adhesive binder; and a photoinitiator, wherein a weight ratio of the polymer additive to the adhesive binder is 0.01% to 4.5%.

The polymer containing a (meth)acrylate-based functional group and a non-polar functional group may include a repeat unit of the following Chemical Formula 1

In Chemical Formula 1, R₁ is hydrogen, or an alkyl group having a carbon number of 1 to 20; R₂ is hydrogen, an alkyl group having a carbon number of 1 to 20, a polyester group, or a polyether group; and n is an integer of 1 to 300.

The (meth)acrylate-based polymer containing at least one fluorine may include a (meth)acrylate-based polymer substituted with a perfluoroalkyl group having a carbon number of 1 to 10 or a fluorinated alkenyl group having a carbon number of 1 to 10.

The silicon-modified (meth)acrylate-based polymer containing a reactive functional group may include a silicon-modified (meth)acrylate-based polymer substituted with at least one reactive functional group selected from the group consisting of a hydroxyl group, an alkylene alcohol having a carbon number of 1 to 10, an epoxy group, an amino group, a thiol group, and a carboxyl group.

The polymer additive may further include at least one organic solvent selected from the group consisting of alcohols, ethers, acetates, or ketones.

The polymer containing a (meth)acrylate-based functional group and a non-polar functional group and the silicon-modified (meth)acrylate-based polymer containing a reactive functional group may respectively have an acid value of 10 mg KOH/g to 50 mg KOH/g, based on an organic solvent of 1 wt % to 50 wt %.

The adhesive binder may include a (meth)acrylate polymer or a (meth)acrylate copolymer unsubstituted or substituted with at least one functional group selected from the group consisting of a hydroxyl group, an isocyanate group, a vinyl group, and a (meth)acrylate group.

The adhesive binder may include an embedded adhesive binder added with an acrylate having a carbon-carbon double bond as a side chain of a (meth)acrylate resin. For example, as the embedded adhesive binder, a polymer resin added with 1 wt % to 45 wt % of a (meth)acrylate functional group as a side chain to the main chain of a (meth)acrylate base resin may be used.

The adhesive binder may include a polymer having a weight average molecular weight of 100,000 to 1,500,000.

The photoinitiator may include at least one selected from the group consisting of benzoins and alkylethers thereof, acetophenones, anthraquinones, thioxanthines, ketals, benzophenones, α-aminoacetophenone, acylphosphine oxides, and oxime esters.

The composition may include 0.01 to 5 parts by weight of the photoinitiator, based on 100 parts by weight of the adhesive binder.

The composition for forming an adhesive layer of a dicing film may further include a curing agent.

The curing agent may include at least one selected from the group consisting of an isocyanate compound, an aziridine compound, an epoxy compound, and a metal chelate compound.

The composition for forming an adhesive layer of a dicing film may include 0.1 to 30 parts by weight of the curing agent, based on 100 parts by weight of the adhesive binder.

Also provided is a dicing film including a base film and an adhesive layer formed on at least one side of the base film, wherein the adhesive layer includes the above-explained composition for forming an adhesive layer of a dicing film.

The thickness of the base film may be 10 μm to 200 μm, and the thickness of the adhesive layer may be 0.5 μm to 50 μm.

Also provided is a dicing die bonding film including the dicing film; and a bonding layer formed on at least one side of the dicing film.

Also provided is a method for dicing a semiconductor wafer including the steps of: conducting pre-treatment by partially treating a semiconductor wafer including the dicing die bonding film and a wafer laminated on at least one side of the dicing die bonding film so that it is completely cut or it can be cut; expanding the semiconductor wafer after the pre-treatment step; and irradiating UV to the base film of the expanded semiconductor wafer, and picking up individual chips separated by cutting of the semiconductor wafer.

Advantageous Effect of the Invention

A composition for forming an adhesive layer of a dicing film for providing a dicing die bonding film that can prevent fixation between films in a dicing process to increase pick-up success rate and exhibit relatively high die shear strength to prevent delamination due to degradation of adhesion strength, a dicing film including an adhesive layer including the composition, a dicing die bonding film including the dicing film, and a method for dicing a semiconductor wafer using the dicing die bonding film are provided.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a dicing film, a dicing die bonding film, and a method for dicing a semiconductor wafer according to specific embodiments will be explained in detail.

According to one embodiment of the invention, a composition for forming an adhesive layer of a dicing film is provided, including: a polymer additive including at least one polymer selected from the group consisting of a polymer containing a (meth)acrylate-based functional group and a non-polar functional group, a (meth)acrylate-based polymer containing at least one fluorine, and a silicon-modified (meth)acrylate-based polymer containing a reactive functional group; an adhesive binder; and a photoinitiator, wherein a weight ratio of the polymer additive to the adhesive binder is 0.01% to 4.5%.

Previously, there was a problem in that a success rate of picking up of chips may be lowered due to fixation between films during a pick-up process in a dicing process and excessive peel strength.

Thus, the inventors confirmed through experiments that if a dicing film including an adhesive layer formed from a composition for forming an adhesive layer of a dicing film, which includes a polymer additive including at least one polymer selected from the group consisting of a polymer containing a (meth)acrylate-based functional group and a non-polar functional group, a (meth)acrylate-based polymer containing at least one fluorine, and a silicon-modified (meth)acrylate-based polymer containing a reactive functional group in a specific content, is used, fixation between films may be prevented and peel strength between films may be lowered to improve a success rate of picking up of chips, relatively high die shear strength may be exhibited to prevent delamination due to degradation of adhesion strength, and reliability of a semiconductor manufacturing process may be improved, and completed the invention.

The polymer containing a (meth)acrylate-based functional group and a non-polar functional group, the (meth)acrylate-based polymer containing at least one fluorine, and the silicon-modified (meth)acrylate-based polymer containing a reactive functional group may be respectively exposed to the top of the adhesive layer prepared from the composition to afford releasability and slip property, while having more compatibility with the adhesive binder on the surface of the adhesive layer and thus being easily mixed.

Thus, the polymer additive may react with the adhesive binder to minimize transcription, and simultaneously, the above-explained non-polar part is located on the surface of the adhesive layer to effectively afford releasability and slip property.

Particular, the polymer additive may be used in the amount of 0.01 wt % to 4.5 wt %, or 0.1 wt % to 2 wt %, based on the adhesive binder, and despite the relatively low use amount, it may significantly decrease peel strength, for example, 180 degree peel strength and tack force before/after UV irradiation and SUS peel strength of the adhesive layer of a dicing film prepared from the composition for forming an adhesive layer of a dicing film of the above embodiment.

If the weight ratio of the polymer additive to the adhesive binder is too low, the adhesive layer of a dicing film prepared from the composition for forming an adhesive layer of a dicing film according to the above embodiment may have significantly increased peel strength, for example, significantly increased 180 degree peel strength and tack force before/after UV irradiation, and SUS peel strength.

Further, if the weight ratio of the polymer additive to the adhesive binder is too high, although peel strength of the adhesive layer of a dicing film prepared from the composition for forming an adhesive layer of a dicing film according to the above embodiment may be lowered to some degree, die shear strength of the adhesive layer may be significantly decreased to generate delamination due to degradation of adhesion strength, and thus reliability may be decreased in a semiconductor manufacturing process.

The polymer containing a (meth)acrylate-based functional group and a non-polar functional group may include a repeat unit of the following Chemical Formula 1.

In the Chemical Formula 1, R₁ is hydrogen, or an alkyl group having a carbon number of 1 to 20; R₂ is hydrogen, an alkyl group having a carbon number of 1 to 20, a polyester group, or a polyether group; and n is an integer of 1 to 300.

Specific examples of the polymer containing a (meth)acrylate-based functional group and a non-polar functional group may include BYK0-350, BYK-352, BYK-354, BYK-355, BYK-356, BYK-358N, BYK-361N, BYK-380, BYK-392, BYK-394, and the like, but are not limited thereto.

The (meth)acrylate-based polymer containing at least one fluorine may include (meth)acrylate-based polymer substituted with a perfluoroalkyl group having a carbon number of 1 to 10 or a fluorinated alkenyl group having a carbon number of 1 to 10.

Specific examples of the commercially available products of the (meth)acrylate-based polymer containing at least one fluorine may include Ftergent 222F (manufactured by NEOS Co. Ltd.), F470 (DIC Corporation), F489 (DIC Corporation), V-8FM, and the like, but are not limited thereto.

The silicon-modified (meth)acrylate-based polymer containing a reactive functional group may include a silicon-modified (meth)acrylate-based polymer substituted with at least one reactive functional group selected from the group consisting of a hydroxyl group, an alkylene alcohol having a carbon number of 1 to 10, an epoxy group, an amino group, a thiol group, or a carboxyl group.

Specific examples of the silicon-modified (meth)acrylate-based polymer containing a reactive functional group may include a hydroxyl functionally modified polyacrylate, and specific examples of the commercially available products thereof may include BYK-SILCLEAN 3700 and the like, but are not limited thereto.

The polymer additive including at least one polymer selected from the group consisting of a polymer containing a (meth)acrylate-based functional group and a non-polar functional group, a (meth)acrylate-based polymer containing at least one fluorine, and a silicon-modified (meth)acrylate-based polymer containing a reactive functional group may further include at least one organic solvent selected from the group consisting of alcohols, ethers, acetates, or ketones.

The polymer additive may include 1 to 50 wt % of the above-explained polymer and a remaining amount of the organic solvent.

The polymer containing a (meth)acrylate-based functional group and a non-polar functional group, and the silicon-modified (meth)acrylate-based polymer containing a reactive functional group may respectively have an acid value of 10 mg KOH/g to 50 mg KOH/g, or 20 mg KOH/g to 40 mg KOH/g, based on an organic solvent of 1 wt % to 50 wt %.

Meanwhile, as the adhesive binder, a polymer resin known to be used for forming an adhesive layer of a dicing film may be used without specific limitations, and for example, a polymer resin substituted with a specific reactive functional group or a polymer resin having a main chain including a reactive functional group may be used.

Specifically, the adhesive binder may include a (meth)acrylate polymer or (meth)acrylate copolymer unsubstituted or substituted with at least one functional group selected from the group consisting of a hydroxyl group, an isocyanate group, a vinyl group, and a (meth)acrylate group.

Further, the adhesive binder may be an embedded adhesive binder added with an acrylate having a carbon-carbon double bond as a side chain of a (meth)acrylate resin. For example, as the embedded adhesive binder, a polymer resin added with 1 wt % to 45 wt % of a (meth)acrylate functional group as a side chain to a main chain of a (meth)acrylate base resin may be used.

The adhesive binder may include a polymer resin having a weight average molecular weight of 100,000 to 1,500,000.

Specifically, the (meth)acrylate polymer or (meth)acrylate copolymer unsubstituted or substituted with at least one functional group selected from the group consisting of a hydroxyl group, an isocyanate group, a vinyl group, and a (meth)acrylate group may have a weight average molecular weight of 100,000 to 1,500,000.

As used herein, (meth)acrylate means to include both acrylate and (meth)acrylate.

Examples of the (meth)acrylate polymer or (meth)acrylate copolymer may include a polymer or copolymer of (meth)acrylic acid ester monomers and monomers containing crosslinkable functional groups.

Herein, examples of the (meth)acrylic acid ester monomers may include alkyl (meth)acrylate, and more specifically, examples of the monomers having a C1-20 alkyl group may include pentyl (meth)acrylate, n-butyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, or decyl (meth)acrylate, or a mixture of two or more kinds thereof. As a monomer having a higher alkyl number is used, the glass transition temperature of the final copolymer decreases, and thus appropriate monomers may be selected according to a desired glass transition temperature.

Examples of the monomers containing a crosslinkable functional group may include hydroxyl group containing monomers, a carboxyl group containing monomers, nitrogen containing monomers, or a mixture of two or more kinds thereof. Examples of the hydroxyl group containing compound may include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and the like, examples of the carboxyl group containing compound may include (meth)acrylic acid and the like, and examples of the nitrogen containing monomers may include (meth)acrylionitrile, N-vinyl pyrrolidone, N-vinyl caprolactam, and the like, but are not limited thereto. The (meth)acrylate-based resin may further include vinyl acetate, a styrene, or an acrylonitrile carbon-carbon double bond-containing low molecular weight compound, and the like, in terms of improvement in other performances such as compatibility and the like.

The embedded adhesive binder added with acrylate having a carbon-carbon double bond as a side chain of a (meth)acrylate resin may have a weight average molecular weight of 100,000 to 1,500,000.

If the weight average molecular weight of the polymer resin included in the adhesive binder is too low, coatability or cohesiveness of the composition for forming an adhesive layer of a dicing film according to the above embodiment may be degraded, and when delaminating an adhesive layer formed from the composition, a residue may remain in the adherend or the adhesive layer may be broken.

If the weight average molecular weight of the polymer resin included in the adhesive binder is too high, UV curing of the composition for forming an adhesive layer of a dicing film according to the above embodiment may not sufficiently occur, and thus peel strength of the adhesive layer formed from the composition may not be sufficiently lowered to decrease the pick-up success rate.

The composition for forming an adhesive layer of a dicing film may further include a UV curable compound.

The kinds of the UV curable compound are not specifically limited, and for example, multifunctional compounds having weight average molecular weight of about 500 to 300,000 (e.g., a multifunctional urethane acrylate, a multifunctional acrylate monomer or oligomer, and the like) may be used. One of ordinary knowledge in the art can easily select appropriate compounds according to desired use.

The content of the UV curable compound may be 5 parts by weight to 400 parts by weight, preferably 10 parts by weight to 200 parts by weight, based on 100 parts by weight of the above-explained adhesive binder. If the content of the UV curable compound is less than 5 parts by weight, a decrease in adhesion strength after curing may not be sufficient and thus pick-up may be degraded, and if it is greater than 400 parts by weight, cohesiveness of the adhesive before UV irradiation may be insufficient, or there is a concern that delamination with a release film and the like may not be easily achieved.

Specific examples of the photoinitiator included in the composition for forming an adhesive layer of a dicing film are not specifically limited, and commonly known photoinitiators may be used without specific limitations. As examples, as the photoinitiator, benzoins and alkylethers thereof, acetophenones, anthraquinones, thioxanthines, ketals, benzophenones, α-aminoacetophenone, acylphosphine oxides, oxime esters, or a mixture of two or more kinds thereof may be used.

The amount of the photoinitiator may be determined considering physical properties and characteristics of the prepared adhesive layer and the kinds and characteristics of the used adhesive binder and the like, and for example, the composition for forming an adhesive layer of a dicing film may include 0.01 to 8 parts by weight of the photoinitiator, based on 100 parts by weight of the adhesive binder.

The composition for forming an adhesive layer of a dicing film may further include a curing agent. When the composition for forming an adhesive layer of a dicing film is coated on a base film, the curing agent may react with the reactive group of the adhesive binder at room temperature or at a temperature of 30 to 50 C to form a crosslink. The specific reactive groups included in the curing agent may remain unreacted, and may be further crosslinked through UV irradiation before pick-up, thus decreasing adhesion strength of the adhesive layer.

The curing agent may include at least one selected from the group consisting of an isocyanate compound, an aziridine compound, an epoxy compound, and a metal chelate compound.

The amount of the curing agent may be determined considering physical properties and characteristics of the prepared adhesive layer and the kinds and characteristics of the used adhesive binder and the like, and for example, the composition for forming an adhesive layer of a dicing film may include 0.1 to 30 parts by weight of the curing agent, based on 100 parts by weight of the adhesive binder.

According to another embodiment, a dicing film including a base film and an adhesive layer formed on at least one side of the base film is provided, wherein the adhesive layer includes the composition for forming an adhesive layer of a dicing film according to the above-explained embodiment.

The kinds of the base film are not specifically limited, and for example, plastic films or metal foils and the like known in this field may be used. For example, the base film may include a low density polyethylene, a linear polyethylene, a medium density polyethylene, a high density polyethylene, a super low density polyethylene, a polypropylene random copolymer, a polypropylene block copolymer, a homopolypropylene, polymethylpentene, an ethylene-vinyl acetate copolymer, an ethylene-methacrylic acid copolymer, an ethylene-methylmethacrylate copolymer, an ethylene-ionomer copolymer, an ethylene-vinyl alcohol copolymer, polybutene, a styrene copolymer, or a mixture of two or more kinds thereof. The base film including a mixture of two or more kinds of the polymers includes both a stacked structure of two or more films respectively including the above-explained polymers, and a single layer of a film including two or more kinds of the above-explained polymers.

The thickness of the base film is not specifically limited, and commonly, it may be formed to a thickness of 10 μm to 200 μm, preferably 50 μm to 180 μm. If the thickness is less than 10 μm, control of cut depth may be unstable in a dicing process, and if it is greater than 200 μm, burrs may be generated in quantity in a dicing process, or elongation may decrease, and thus an expanding process may not be exactly achieved.

The base film, if necessary, may be subjected to a common physical or chemical treatment such as matt treatment, corona discharge, primer treatment, crosslinking, and the like.

The thickness of the adhesive layer may be 0.5 μm to 50 μm, or 5 μm to 30 μm.

The details of the composition for forming an adhesive layer of a dicing film that is included in the adhesive layer includes all the contents explained above.

According to still another embodiment of the invention, a dicing die bonding film including the dicing film, and a bonding layer formed on at least one side of the dicing film, are provided.

The details of the dicing film includes all the contents explained above.

The bonding layer may include an epoxy resin, a low elastic high molecular weight resin, and a curing agent for the bonding layer. The epoxy resin may include a common epoxy resin for adhesive known in this field, and for example, an epoxy resin containing two or more epoxy groups in the molecule and having a weight average molecular weight of 100 to 5000 may be used.

The epoxy resin may form a hard crosslinking structure through a curing process to exhibit an outstanding adhesion property, heat resistance, and mechanical strength.

More specifically, as the epoxy resin, it is particularly preferable to use those having an epoxy equivalent of 100 to 1000. If the epoxy equivalent of the epoxy resin is less than 100, crosslinking density may become too high, and thus the bonding film may exhibit generally hard properties, and if the epoxy equivalent of the epoxy resin is greater than 1000, heat resistance may be degraded.

Specific examples of the epoxy resin may include: a difunctional epoxy resin such as bisphenol A epoxy resin or bisphenol F epoxy resin and the like; or a multifunctional epoxy resin having 3 or more functional groups such as a cresol novolac epoxy resin, a phenol novolac epoxy resin, a tetrafunctional epoxy resin, a biphenyl-type epoxy resin, a triphenolmethane-type epoxy resin, an alkyl modified triphenolmethane-type epoxy resin, a naphthalene-type epoxy resin, a dicyclopentadiene-type epoxy resin, a dicylcopentadiene modified phenol-type epoxy resin, and the like, or a mixture of two or more kinds thereof, but are not limited thereto.

It is preferable to use a mixed resin of a difunctional epoxy resin and a multifunctional epoxy resin as the epoxy resin.

The r multifunctional epoxy resin means an epoxy resin having 3 or more functional groups. That is, a difunctional epoxy resin generally has excellent flexibility and high temperature flowability and the like, but has inferior heat resistance and curing speed, while a multifunctional epoxy resin having 3 or more functional groups has a rapid curing speed and exhibits outstanding heat resistance due to high crosslinking density, but has inferior flexibility and flowability. Thus, by appropriately mixing the two kinds of resins, scattering of chips or incidence of burrs may be inhibited in a dicing process, while controlling elasticity and tack property of the bonding layer.

The low elastic high molecular weight resin may form a soft segment in the adhesive to afford stress relaxation at a high temperature. As the high molecular weight resin, any resin may be used as long as it does not induce breaking when blended with the epoxy resin to form a film, can exhibit viscoelasticity after forming a crosslinking structure, and has excellent compatibility with other components and storage stability.

Specific kinds of the low elastic high molecular weight resin are not specifically limited as long as they satisfy the above-explained properties, but for example, polyimide, polyether imide, polyester imide, polyamide, polyether sulfone, polyether ketone, polyolefin, polyvinyl chloride, phenoxy, reactive acrylonitrile butadiene rubber, a (meth)acrylate-based resin, and the like, or a mixture of two or more kinds thereof, may be used.

Specific examples of the (meth)acrylate-based resin may include an acryl based copolymer including (meth)acrylic acid and derivatives thereof, wherein examples of the (meth)acrylic acid and derivatives thereof may include (meth)acrylic acid, an alkyl (meth)acrylate containing a C1-12 alkyl group such as methyl (meth)acrylate or ethyl (meth)acrylate and the like, (meth)acrylonitrile or (meth)acrylamide, and other copolymerizable monomers.

The (meth)acrylate-based resin may include one kind or two or more kinds of functional groups such as a glycidyl group, a hydroxyl group, a carboxyl group, an amine group, and the like, which can be introduced by copolymerizing monomers such as glycidyl (meth)acrylate, hydroxyl (meth)acrylate, hydroxyethyl (meth)acrylate, carboxy (meth)acrylate, or the like.

The curing agent that can be included in the adhesive composition is not specifically limited as long as it can react with the epoxy resin and/or low elastic high molecular weight resin to form a crosslinking structure. For example, a curing agent capable of reacting with the two components to form a crosslinking structure may be used, and such a curing agent forms crosslinking structures respectively with soft segments and hard segments in the adhesive to improve heat resistance, and simultaneously acts as a crosslinking agent of both segments at the interface thereof to improve reliability of a semiconductor package.

The thickness of the bonding layer, although not specifically limited, may be 1 μm to 100 μm, or 3 μm to 50 μm, for example.

According to yet another embodiment of the invention, a method for dicing a semiconductor wafer is provided, including the steps of: conducting pre-treatment by partially treating a semiconductor wafer including the above dicing die bonding film and a wafer laminated on at least one side of the dicing die bonding film so that it is completely cut or it can be cut; expanding the semiconductor wafer after the pre-treatment step; and irradiating UV to the base film of the expanded semiconductor wafer, and picking up individual chips separated by cutting of the semiconductor wafer.

The details of the dicing die bonding film include all the contents explained above.

Except the details of the steps of the dicing method, commonly known apparatuses used for dicing of a semiconductor wafer, dicing methods, and the like may be used without specific limitations.

By using the dicing die bonding film including the dicing film, incidence of burrs may be minimized during a dicing process of a semiconductor wafer to prevent pollution of semiconductor chips and improve reliability and lifespan of semiconductor chips.

Specific embodiments of the invention will be explained in detail in the following examples. However, these examples are only to illustrate specific embodiments of the invention, and the scope of the invention is not limited thereto.

Example 1

Based on 100 parts by weight of a photo-curable adhesive binder resin, 2 parts by weight of an isocyanate-based curing agent (multifunctional isocyanate oligomer), 0.2 parts by weight of BYK-SILCLEAN (BYK Company), and 1 part by weight of DAROCUR TPO as a photoinitiator were mixed to prepare a UV-curable adhesive composition. As the photocurable adhesive binder resin, a polymer resin added with 20 wt % of acrylate functional groups as a side chain to the main chain of acrylic base resin (Mw 300,000) was used.

The UV-curable adhesive composition was coated on one side of a 100 um polyolefin film, and dried to prepare a dicing film including a 10 um thick adhesive layer.

Example 2

Based on 100 parts by weight of a photo-curable adhesive binder resin, 2 parts by weight of an isocyanate-based curing agent (multifunctional isocyanate oligomer), 0.2 parts by weight of BYK-SILCLEAN 394 (BYK Company), and 1 part by weight of DAROCUR TPO as a photoinitiator were mixed to prepare a UV-curable adhesive composition. As the photocurable adhesive binder resin, a polymer resin added with 20 wt % of acrylate functional groups as a side chain to the main chain of acrylic base resin (Mw 300,000) was used.

The UV-curable adhesive composition was coated on one side of a 100 um thick polyolefin film, and dried to prepare a dicing film including a 10 um thick adhesive layer.

Comparative Example 1

Based on 100 parts by weight of a photo-curable adhesive binder resin, 2 parts by weight of an isocyanate-based curing agent (multifunctional isocyanate oligomer) and 1 part by weight of DAROCUR TPO as a photoinitiator were mixed to prepare a UV-curable adhesive composition. As the photocurable adhesive binder resin, a polymer resin added with 20 wt % of acrylate functional groups as a side chain to the main chain of acrylic base resin (Mw 300,000) was used.

The UV-curable adhesive composition was coated on one side of a 100 um thick polyolefin film, and dried to prepare a dicing film including a 10 um thick adhesive layer.

Comparative Example 2

Based on 100 parts by weight of a photo-curable adhesive binder resin, 2 parts by weight of an isocyanate-based curing agent (multifunctional isocyanate oligomer), 5 parts by weight of BYK-SILCLEAN 3700 (BYK Company), and 1 part by weight of DAROCUR TPO as a photoinitiator were mixed to prepare a UV-curable adhesive composition. As the photocurable adhesive binder resin, polymer resin added with 20 wt % of acrylate functional groups as a side chain to the main chain of acrylic base resin (Mw 300,000) was used.

The UV-curable adhesive composition was coated on one side of a 100 um thick polyolefin film, and dried to prepare a dicing film including a 10 um thick adhesive layer.

Comparative Example 3

Based on 100 parts by weight of a photo-curable adhesive binder resin, 2 parts by weight of an isocyanate-based curing agent (multifunctional isocyanate oligomer), 0.5 parts by weight of a silicon compound oil L-7500 (Silvet Company), and 1 part by weight of DAROCUR TPO as a photoinitiator were mixed to prepare a UV-curable adhesive composition. As the photocurable adhesive binder resin, a polymer resin added with 20 wt % of acrylate functional groups as a side chain to the main chain of acrylic base resin (Mw 300,000) was used.

The UV-curable adhesive composition was coated on one side of a 100 um thick polyolefin film, and dried to prepare a dicing film including a 10 um thick adhesive layer.

Experimental Example

The peel strengths, tack forces and pick up success rates of the dicing films prepared in Examples 1 and 2 and Comparative Examples 1 to 3 were measured as follows, and the results are shown in the following Tables 1 and 2.

1. Measurement of 180 Degree Peel Strength Between Die Bonding Film/Dicing Film (Before/after UV Curing)

In order to measure peel strength between a die bonding film and a PSA layer, a bonding film was laminated with a dicing film at room temperature, allowed to stand for 1 hour, a sample with a width of 25 mm was manufactured, and 180 degree peel strength was measured at a speed of 300 mm/min, and additionally, the value after UV curing was measured. The measurement was conducted three or more times per sample, and the mean value was recorded.

2. Measurement of 90 Degree Peel Strength Between SUS/Dicing Film (Before UV Curing)

A dicing film having a width of 25 mm was prepared, and attached to an adherend of SUS 304. After 1 hour of curing, 90 degree peel strength was measured at a speed of 300 mm/min. The measurement was conducted three or more times per sample, and the mean value was recorded.

3. Tack Test (Before/after UV Curing)

The dicing film was put on a plate so that the adhesive layer faced upward, and tack force was measured using a ball-type probe having a diameter of 1 inch. Herein, the force applied to the probe was 800 gf, the contact time was 0.01 second, the measurement speed for tearing off the probe was 1 mm/s, and the apparatus used for measurement was a Texture Analyzer.

4. Measurement of Pick-Up Success Rate

The dicing die bonding films prepared from the dicing films of the examples and comparative examples were laminated with wafers at 70° C. Subsequently, a dicing process was conducted using a dicing apparatus (manufactured by NEON Company) under the following conditions, and then UV was irradiated to the dicing film side under the following conditions. Thereafter, 200 chips were picked up with a die bonder (Shinkawa Co. Ltd.), and the number of non-picked-up chips was measured and recorded as a percent.

[Dicing Conditions]

Blade: 27HEDD

Blade rotation speed: 40,000 rpm

Speed: 30 mm/s

Chip size: 10 mm×10 mm

Cut depth: 70 um

[UV Irradiation Conditions]

Lamp: metal halide type

Intensity of illumination: 70 mW/cm² (measured with UV meter)

Irradiation amount: 200 mJ/cm² or more (measured with UV meter)

[Pick Up Conditions]

Expanding: 4 mm

Pin height: 0.15 mm

Pick up strength: 100 gf

5. Die Shear Strength

A wafer having a 500 um thickness coated with a dioxide layer was cut to a size of 5 mm×5 mm, and laminated with a dicing die bonding film at 60° C., followed by UV irradiation to remove the dicing film and cutting to leave only a bonding film of a chip size. The upper chip of a 5 mm×5 mm size was put on the lower chip of a 10 mm×10 mm size, and then pressed with a force of 2 kgf for 2 seconds on a hot plate at 130° C., followed by curing at 125° C. for 1 hour. The above manufactured test piece was cured at 175° C. for 2 hours, and then die shear strength of the upper chip was measured at 250° C.

TABLE 1 Example 1 Example 2 180 degree peel Before UV irradiation 355.6 384.5 strength (unit: gf/25 mm) After UV irradiation 8.3 9.0 SUS peel strength (unit: gf/25 mm) 168.4 178.2 Tack force (unit: gf) Before UV irradiation 158.2 170.5 After UV irradiation 0.57 0.63 Pick-up success rate (%) 100 97 Die shear strength (unit: kgf/chip) 10.4 10.2

TABLE 2 Comparative Comparative Comparative Example 1 Example 2 Example 3 180 degree peel Before UV 492.3 154.7 189.5 strength (unit: irradiation gf/25 mm) After UV 11.2 7.9 8.5 irradiation SUS peel strength 267.0 132.5 171.7 (unit: gf/25 mm) Tack force Before UV 209.4 81.1 91.1 (unit: gf) irradiation After UV 1.53 0.42 0.55 irradiation Pick-up success rate (%) 73.5 100 100 Die shear strength 10.5 3.4 5.8 (unit: kgf/chip)

As shown in the Table 1 and Table 2, it was confirmed that the dicing films prepared in Examples 1 and 2 exhibit relatively low 180 degree peel strength and tack force before/after UV curing, relatively low SUS peel strength, and high pick-up success rate, compared to the dicing film prepared in Comparative Example 1.

Furthermore, it was confirmed that the dicing films prepared in Examples 1 and 2 exhibit relatively high die shear strength compared to the dicing films prepared in Comparative Examples 2 and 3, to prevent delamination due to a decrease in adhesion strength, thus inhibiting reflow cracks and improving reliability of a semiconductor manufacturing process. 

What is claimed is:
 1. A composition for forming an adhesive layer of a dicing film, comprising: a polymer additive comprising at least one polymer selected from the group consisting of a polymer containing a (meth)acrylate-based functional group and a non-polar functional group, a (meth)acrylate-based polymer containing at least one fluorine, and a silicon-modified (meth)acrylate-based polymer containing a reactive functional group; an adhesive binder; and a photoinitiator, wherein a weight ratio of the polymer additive to the adhesive binder is 0.01% to 4.5%.
 2. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the polymer containing a (meth)acrylate-based functional group and a non-polar functional group includes a repeat unit of the following Chemical Formula 1:

wherein, in Chemical Formula 1, R₁ is hydrogen, or an alkyl group having a carbon number of 1 to 20, R₂ is hydrogen, an alkyl group having a carbon number of 1 to 20, a polyester group, or a polyether group, and n is an integer of 1 to
 300. 3. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the (meth)acrylate-based polymer containing at least one fluorine includes a (meth)acrylate-based polymer substituted with a perfluoroalkyl group having a carbon number of 1 to 10 or a fluorinated alkenyl group having a carbon number of 1 to
 10. 4. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the silicon-modified (meth)acrylate-based polymer containing a reactive functional group includes silicon-modified (meth)acrylate-based polymer substituted with at least one reactive functional group selected from the group consisting of a hydroxyl group, an alkylene alcohol having a carbon number of 1 to 10, an epoxy group, an amino group, a thiol group, or a carboxyl group.
 5. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the polymer additive further comprises at least one organic solvent selected from the group consisting of alcohols, ethers, acetates, or ketones.
 6. The composition for forming an adhesive layer of a dicing film according to claim 5, wherein the polymer containing a (meth)acrylate-based functional group and a non-polar functional group and the silicon-modified (meth)acrylate-based polymer containing a reactive functional group respectively have an acid value of 10 mg KOH/g to 50 mg KOH/g, based on an organic solvent of 1 wt % to 50 wt %.
 7. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the adhesive binder includes a (meth)acrylate-based polymer or a (meth)acrylate-based copolymer unsubstituted or substituted with at least one functional group selected from the group consisting of a hydroxyl group, an isocyanate group, a vinyl group, and a (meth)acrylate group.
 8. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the adhesive binder includes an embedded adhesive binder added with an acrylate having a carbon-carbon double bond as a side chain of a (meth)acrylate resin.
 9. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the adhesive binder includes polymer resin having a weight average molecular weight of 100,000 to 1,500,000.
 10. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the photoinitiator includes at least one selected from the group consisting of benzoins and alkylethers thereof, acetophenones, anthraquinones, thioxanthines, ketals, benzophenones, α-aminoacetophenone, acylphosphine oxides, and oxime esters.
 11. The composition for forming an adhesive layer of a dicing film according to claim 1, wherein the composition for forming an adhesive layer of a dicing film comprises 0.01 to 8 parts by weight of the photoinitiator, based on 100 parts by weight of the adhesive binder.
 12. The composition for forming an adhesive layer of a dicing film according to claim 1, further comprising a curing agent.
 13. The composition for forming an adhesive layer of a dicing film according to claim 12, wherein the curing agent includes at least one selected from the group consisting of an isocyanate compound, an aziridine compound, an epoxy compound, and a metal chelate compound.
 14. The composition for forming an adhesive layer of a dicing film according to claim 12, wherein the composition for forming an adhesive layer of a dicing film comprises 0.1 to 30 parts by weight of the curing agent, based on 100 parts by weight of the adhesive binder.
 15. A dicing film comprising a base film, and an adhesive layer formed on at least one side of the base film, wherein the adhesive layer comprises the composition for forming an adhesive layer of a dicing film of claim
 1. 16. The dicing film according to claim 15, wherein the thickness of the base film is 10 μm to 200 μm, and the thickness of the adhesive layer is 0.5 μm to 50 μm.
 17. A dicing die bonding film comprising the dicing film of claim 15, and a bonding layer formed on at least one side of the dicing film.
 18. A method for dicing a semiconductor wafer, comprising the steps of: conducting pre-treatment by partially treating a semiconductor wafer comprising the dicing die bonding film of claim 17 and a wafer laminated on at least one side of the dicing die bonding film so that it is completely cut or the semiconductor wafer can be cut; expanding the semiconductor wafer after the pre-treatment; and irradiating UV to the base film of the expanded semiconductor wafer, and picking up individual chips separated by cutting of the semiconductor wafer. 